WESTERN BIRDS Sparrows 



GENUS MELOSPIZA: SONG SPAR- 

 EOWS. 



Probably most bird lovers are familiar with the little 

 Song Sparrow, although I presume that few of them 

 realize how many forms this bird assumes in the North 

 American continent. While east of the Rockies it shows 

 but little individual variation, M. melodia melodia be- 

 ing the common Sparrow and the only other one being 

 Judd's (M. m. juddi), which is slightly grayer and found 

 in North Dakota, west of the Rockies; there are twenty- 

 one subspecies, two of which (M. m. montana and M. m. 

 merrilli — Mountain and Merrill's) are found in the 

 region of the Rocky Mountain Range, all the others 

 ranging along the Pacific Coast from Alaska to southern 

 Mexico. 



Dr. Frank M. Chapman, in Vol. 12 of "Bird-Lore," 

 gives a comprehensive article about the range and vary- 

 ing plumage of these birds. 



He says that "the Song Sparrow is the most plastic 

 of North American birds, or, in other words, it is so 

 readily affected in size and color by the climatic condi- 

 tions under which it lives that, given some slight change 

 in the climate of a region, we expect to find it reflected 

 in the Song Sparrow of that region. Broadly speaking, 

 the general colors of Song Sparrows are related to the 

 rainfall, while their size is related to latitude. Thus the 

 Song Sparrows of arid regions are pale, while the Song 

 Sparrows of humid regions are dark. For instance, the 

 Desert Song Sparrow which inhabits the Colorado desert, 

 where the annual rainfall averages about six inches, is 

 light colored and pale looking; while the Sooty Song 

 Sparrow that lives on the northwest Pacific coast, where 

 the annual rainfall averages over ninety inches, is dark 

 and rich in coloring. 



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